Yesterday we discussed the software,
compression, and hardware requirements, but what machines are good
for this sort of thing?
Apple has always been a leader in media manipulation (literally
or figuratively?), producing many different audio/video capable
Macs over the years. Starting with the 68040 based Quadras,
built-in video in/out capability allowed anyone to be a
director.
However, with the availability of USB and FireWire based analog
capture solutions, spending any amount of money on an older Mac is
questionable. I'd say the limit is about $100 - the price of a USB
analog capture device (
ATI's Xclaim TV USB Edition).
However, if you've already got one of these machines or can
obtain one on the cheap, you can probably put it to good use.
Also, your local camera shop may provide video transfer
services, taking your VHS or 8mm tapes and copying them to VCD or
DVD. Some outfits charge less than $100 for a two hour tape. If
you're just doing a one-off, this may be a better route than doing
it yourself. Note that you'll still need enough computing power to
edit the digitized product.
68K Machines
The aforementioned Quadras (660av, 840av) are the best bet for video
capture among 68k machines. Their standard configuration is
8 MB of RAM with 230 MB hard drives.
Since they're NuBus-based, the Quadras have some video quirks
which must be addressed. When working with video, the VRAM is
equally shared between graphics (i.e.: Finder) and video (the video
signal sent into the computer). This means you're limited to
certain resolutions and color depths, depending on the amount of
VRAM in the machine (for the 840av, 1 MB standard, 2 MB
max.) Composite (RCA) and S-video connectors are built in, so you
can hook up a video camera or DVD player.
As a stock machine, the Quadras are fine for capturing still
images, but they're inadequate for capturing high quality video.
You'll need to add more RAM and a larger hard drive or find a used
machine that fits the bill; 64 MB of RAM and a 500 MB hard drive is
practical; more is better.
Even with more RAM and a bigger hard drive, capture performance
is hampered by the 40 MHz processor - 10 fps at 160 x 120
resolution is typical (less than VHS quality). This can be improved
by compressing the video after capturing (which requires more hard
drive space) and/or capturing directly to RAM (this limits the size
of the video clip to a few seconds). With these limitations, the
Quadras are still useful as webcams or for capturing small, short
videos for email or the Web.
Some Quadras come equipped with a hardware compression card
(i.e., SpigotPro AV) which allows for full frame, full motion video
capture (640 x 480 at 30 fps). I wouldn't mind spending $100 on one
of these machines; you can set it up for video capture only, then
send the files over ethernet to a faster Mac for editing.
NuBus PowerMacs
AV equipped Macs in the x100 series (Power Mac 6100, 7100, and 8100)
came standard with 16 MB or more RAM and 500 MB or larger hard
drives, which makes them a little bit better than the Quadras. They
can achieve better results than their 68k cousins, but they're
still limited in their usage of VRAM (same graphics/video split)
and connectors (S-video only, no composite). This means you'll need
to shell out for special S-video to RCA cables if you want to hook
up a video camera or VCR.
The AV card's circuitry is nearly identical to that of the
Quadras, so performance is very similar. With the PowerPC
processors in these Macs, it's possible to capture compressed
video, and higher frame rates (15-20 fps) at higher resolutions
(320 x 240) are possible with uncompressed video. This makes the
limiting factors the system bus and hard drive space, which are
still in the class of 68k machines.
x100 series machines are readily available and dirt cheap on the
used market these days, but don't pay more than $50 unless it comes
with a large hard drive (9 GB) and lots of RAM (64 MB+).
Hardware compression cards, while available, are either scarce
or insanely expensive, and cards that worked in the 68k machines
were often buggy in PowerPC machines. Vendors quickly abandoned any
fixes after Apple adopted the much more robust PCI
architecture.
Pre-G3 PCI Power Macs
Apple produced many AV equipped pre-G3 PCI Macs, including those
in the x500 and x600 series. Macs with built-in S-video or
composite ports are ideal for low resolution video capture: faster
processors combined with the speedy PCI bus make for much better
results than NuBus systems. You can capture uncompressed, full
motion, low resolution video (320 x 240, VHS quality) or, with
compression, the same resolution with a lower frame rate.
The video quirks of NuBus systems are gone; whatever color depth
your monitor is set at is what you'll capture. For best results,
this should be 16-bit (thousands of colors) or 24-bit (millions of
colors).
PCI Macs are still somewhat pricey on the used market; x500 or
x600 series machines haven't hit the sub-$100 mark yet. These
machines often shipped with 32 MB+ of RAM and 1 GB+ hard
drives, and they are easily upgraded with a G3 or G4 processor.
However, by the time you add some more RAM and a larger hard drive,
you may be in the territory of a first
generation G3 (beige), which has a faster system bus and much
cheaper memory.
If your PCI Mac doesn't have video I/O ports, you can add a
capture card. These fall into three general groups: simple TV tuner
or video input cards (as on AV Macs) that digitize the signal but
perform no compression (i.e., iXMicro's iX TV), cards that provide
video input/output and hardware compression (i.e., Pinnacle's
DC30), and professional cards that provide hardware compression
along with other features like real-time 3D effects (i.e., Matrox's
RtMac).
What's the difference between the three? It's all in the edited
final product. With the first two, you can capture video at varying
quality levels, then edit it with your favorite software (Premiere,
Videoshop, etc.). When you're done, you have to sit back and let
the computer render the final product - add all the fades, wipes,
edits, etc. Depending on your computer's speed, this can take
minutes or hours.
With a professional real-time editing card, the rendering is
done by circuitry on the capture card in real-time; there's no
waiting involved. You see the effect of a wipe, fade, or transition
immediately. This is a necessity for professionals, but the cost is
prohibitive for consumers: $800 to thousands of dollars (and that
often does not include the editing software itself.)
Digital Video
What about digital video for older Macs? The addition of a PCI
FireWire (a.k.a. IEEE1394 or iLink) card to your existing Power Mac
is an option. The requirements for analog video are still
applicable (or greater): Even though the compression is all done in
the camera, you still need a large, fast hard drive to keep up.
Editing the video takes a lot of computing horsepower as well, and
DV format is only compatible with newer editing software. Check the
requirements of any card before plunking down your cash or
plastic.
On the other hand, a FireWire port is handy for the new
generation of external devices (hard drives, digicams, etc.). With
prices at $100 or under, it's a worthy upgrade even if you don't
plan on doing a lot of DV transfers.
